Karin and Martin are 39 years married. Karin is a music and yoga teacher, Martin IT consultant, he works three, four days a week in Bonn. Since their four children moved out of the 200 square meter house in the Hamburg hinterland, the two have taken in five refugees and around a thousand couch surfers - travelers from all over the world who spend the night for free. We speak one after another on a bench behind her house.